Coaster-brake.



No. 760,720. f PATBNTB'D. MAY24; 1904.,

J. 'ZIMMERMAN.

G OASTER APPLICATION nun we. as, 1900.

2 SHEETS-SHEET 1,

no MODEL.

- WITNESSES:- INVE 2 'OR 'm: nouns PETERS 00.. Puoroumn. W BMINYOIL-DE 3 which i'sfitted the sprocket.

UNITED "STATES Patented May 24, 1904.

PATENT OFFICE.

JOHN ZIMMERMAN, or SYRACUSE, NEW YORK.

COASTER-BRAKE.

SPECIFICATION forming part of Letters Patent No. 760,720, dated May 24, 1904. I

Application'filed August 25, 1900. Serial No. 28,002. (No model.)

To aZZ whom, it mdy concern: 1 i

Beit known that I, JOHN ZIMMERMAN, of Syracuse, in thecounty of Onondaga, in the State ofwNew York, have'invented new and 5 useful Improvements in Coaster-Brakes, of

which "the following,.taken inconnection with the accompanying drawings,=is a full, clear, and exact description. v r invention is a coaster-brake for bicycles,

1o. simpleand strong in construction and effective inoperation. I

My invention Wlll be understood by refer ence to the accompanying drawings, in which the same reference-numerals indicate the same parts in all the figures;

FigureI isan end elevation. of my brake, port ons being broken away. Fig. II is-a crosssection-of my brake 1n drlving posltion. Fig.

- III is a-correspondin-g'cross-section showing the parts in braking position.

Fig. IV is a cross-section on line IV IV of-Fig. III, showing the outer face ofthe sprocket. I Fig. .V is a a cross-sectionv on line V V'of Fig. II, showing the parts in driving position. FigQVI is 2 5 thesame as Fig-V withthe parts in the coast- Fig. VII'is an end ing or braking position. elevation similar to Fig.1, showing the parts 1n coasting or braking position. VIII IS a longitudinal section'showing the parts sepa rated. Fig. IX is an isometric view of one of the clam ping-pieces. I Fig. X is a section corresponding to Fig. VIII, showing a modification.

Theessential parts of my invention are the hub and the sprocket-ringsecured'thereto, to In the circumfer ences in contact of the sprocket and sprocketring are out two series of cam-slots, larger toward the rear and gradually diminishing toward thefront- The slots in the inner edge 4 of the sprocket are equal or greater in depth, those in the outer circumference ofthe ring less in depth than the diameter of the bind-' ing balls or rollers arranged therein. When "the sprocket is turned forward, these rollers drop into one or more-ofthe sprocket-ring pockets, bindin the narrower portion of the sprocket-slots, and lockthe sprocket to. the

- ring. This is the mechanism for locking the sprocket when the pedals are driving, but'un- 5 looking it when coasting or back-pedaling.

.to move toward or'from the center;

To the sprocket is secured the brake ring having an annular wall of which clamping-see tions or wedging-pieces are separate and free On theirinner edges are friction-surfaces of any desirable form and on their outeredges cam-slots smaller toward the front, in which are arranged I balls or rollers running free in the wider part and binding in the narrower against a'fixed ring surrounding these clamping-sectlons, so

I as toforce' them inwardlyand to force their friction-surfacesagainst a corresponding surface on alock-nut secured to the hub, so brakfmg the wheel. These contact friction-surfaces on the sections and the lock-nut may be of different-forms. Preferably the-lock-nu't is -tapered and-the inner edges of the sections 'in'' clined to-fit so that when forced toward the center they slide in on the taper and force the sprocket in'to frictional engagement with a cOntactsurface I on the sprocket -ring, thu s 'braking-morepowerfully by increase in friction-surfaces. 'These clamping sections are forced "outwardly by springs of any conven -ient form and arrangemen In the drawings, '1 indicates the wheel-hub 'ofu'sual construction, provided with the spokejfiangeQ, the shoulder 3, the right-hand thread :4, and the smaller left-hand thread 5.

On the right-hand thread is secured the sprocket- ;ring 7 having an annular fiber ring or washer" 8, fitted. between" its outer margin 9 and its hub or shank 10, which is formed on its outer- Emargin with a number of recesses gradually diminishing in depth toward the rear. These are. preferably formed with a rear inclined portion 11 and a deeper poeket12 at the front end. At deepest'they are of less-depth than the diameter of the driving balls or rollers 13. There arepreferably several of these pockets in the periphery of the sprocket-ring shank, so that the balls will find one or more to drop into in every position of the wheel. The sprocket 20, with which engages the usual chain from the front sprocket, is fitted to this. shank and is provided on its inner periphery 21 with corresponding recesses 22, gradually increasing in depth toward the front and preferably four or more in number,

so that one may always be at or near the top and instantaneously engaged with at least one ball to drive the wheel, as hereinafter described. These sprocket-recesses are preferably formed at the front with rather a sharp shoulder 23 to engage with the balls and positively pick them out of the pockets 12 when the pedals are stationary for coasting or backpedaling. On its inner face the sprocket is formed with the annular groove 19, fitting the outer margin 9 of the sprocket-ring, that the inner or friction surface 24 of the sprocket may be brought into frictional contact with the fiber ring '8. On its outer face the sprocket is provided with pins 25, which fit holes 26 in the brake-ring 27, attaching it to the sprocket. Screws 28 are provided for the same purpose. This brake-ring is provided with the annular wall 32. Sections of this wall are made separate, forming clampingpieces or wedging-pieces 34, capable of a certain amount of inward and outward motion toward and from the center, and are provided with springs 35, engaging in small grooves 36 to force these movablegripping or clamping pieces outwardly to insure the disengage ment under ordinary conditions of their inclined inner faces 37 from a corresponding surface on the lock-nut. There. may be one or more of these clamping-pieces 34, preferably an opposite pair, as here shown. They are formed on their outer edges with camslots 38, gradually diminishing in depth toward the front, in which are arranged the balls or rollers 39. These rollers, forced into frictional contact with the fixed surrounding ring 41 by springs 35 of any convenient form and arrangement, bind in the narrower portion of the slot in back-pedaling and force in the clamping-pieces against the locknut, so as to bring the friction-surfaces in contact and set the brake. These slots at their deepest are a very little less in depth than the diameter of the rollers. This ring 41 hasa hardened inner surface 42, making contact with the rollers, is counterbored at 43 on its inner edge to fit the annular margin or faceplate 31 of the brake-ring,-and correspondingly counterbored at 44 on its outer face to receive the face-plate of the lock-nut. It is fixed in position by an integral arm 45, secured to one of the fork sides 46 by a clamp of any desirable construction. As here shown, this consists of clamp-arm 47, adjustable by means of slot 48 and secured in position to grip the fork sides by adjusting nut and pin 49, preferably protected by the bushing 51, of rubber or other soft material.

55 is the lock nut, secured to hub by left-hand thread 5, for holding the parts in position and is provided with the annular face-plate 56, fitting the counterbore 44, to cover and protect the parts. This lock-nut is formed with the eounterbore 57, fitting the shank 10, and with the inclined friction-surface 58, fitting and engaging with the inclined surface 37 of the clamping-pieces. Theinner edge of the brake-ring is inclined at 33 to lit the taper on the lock-nut. In this inclined surface 37 of one or more of the clampingpieces may be formed the notches 60, as best shown in Fig. I, for the introduction of the driving-balls when the brake-ring is in position.

The operation is as follows: The driving andreleasing mechanism is best shown in Figs. IV and V, in which the direction of the rotation of the sprocket is indicated by arrows, the sprocket being locked to the sprocket ring and hub by the balls in the pockets 12, with which engage the narrower portion of thecam-slots 22. When it is desired to coast, the sprocket is held stationary by the feet while the sprocket ring and hub continue to revolve, as shown by the arrow in Fig. VI, by which the balls are picked out of their pockets by the shoulders 23, so that the wheel rotates freely. These shoulders engaging with the balls are important, for this positive and continuous picking out of the pockets insures disengagement of the sprocket-ring from the sprocket. The frictional engagement of the clamping-pieces with the look-nut also cooperates to the same effect, and a brake action of considerable power could be applied to the wheel by the grip of the clamping-pieces on the lock-nut without the frictional engagement of the inner face of the sprocket with the fiber ring. In Fig. X I have shown such aconstrnction, in which the inneredges of the clamping-pieces are straight and grip a straight lock-nut, applying all the friction thereto without forcing in the sprocket against the ring. The clampingpieces and lock-nut may be made in any other form to engage; but I consider the construction first described much better, in which there are two sets of friction-surfaces.

The instantaneous reversal and engagement of the parts effected by back-pedaling to set the brake is best shown in Figs. I, VII, .11, and III. In Figs. 1 and II the clamping-pieces are shown in the idle position in which they rest during driving and coasting. \Vhen the brake is to be applied, the sprocket and brakering are turned back, and the rollers 39, held in contact with the fixed ring by the action of the springs, are forced back into the narrower portion of their slots and necessarily force radially the clamping or wedging pieces against the tapering lock-nut, on which they slide down and in, forcing inwardly the brake-ring and sprocket and forcing the inner face of the sprocket against the fiber ring, and thus applying to the wheel a frictional brake of great power. (See Figs. VII and 111.)

My brake is simple, strong, economical, composed of few parts, powerful and positive in operation. It is easy to assemble, the parts are strong, are protected from dirt and damage, are retained in operative position by the form of the parts, and are adaptedfor use with a hub and vehicle of ordinary construction. The axle, ball-bearings, and mode of securing the hub in position are all of usual construction. v

In Fig. VIII is shown an oiling device used, if desired, consisting of fiber, felt, or wicking soaked in oil and introduced into a hole in annular wall 32, oiling a surface at each end. c

Having described my invention. what I claim, and desire to protect-by Letters Patent,

tion-surface thereon, the sprocket, means for locking the sprocket to the hub while driving and releasing therefrom while coasting v or back-pedaling, abrake-ring connected to the sprocket having radial ways, wed ging-sections fitted, to the ways having cam-slots on their outeredges, rotatingelements arranged in the slotsand of larger "diameter than their narrower portions, a fixed ring arranged around A said brake-ringiand sections, inclines fitting withinsaid wedging-sections, and means for limiting the outward movement of the inclines when the wedging-sections are forced toward the center. r

2. In a back-pedaling bicycle-brake, the

I hub, a friction-surface thereon, means for looking thesprocket to the hub when driving and releasing it therefrom when coasting or backpedalmg, a brake ring connected to the sprocket havlng radlal ways, wed ging-sections fitted to the ways, having inclined inner edges and cam-slots in their outer edges, rollers arranged in said cam-slots of larger diameter than the narrower portion of the slots, a fixed ring arranged around thebrake-ring and sec-.

tions, inclines suitably supported and arranged within said wedging-s'ections, and a lock-nut secured to the hub and having an outer faceplate arranged without said inclines.

3. In combination in a coaster-brake for velocipedes, the wheel, the hub, the sprocket, means for locking the sprocket to the hub when driving and for releasing it therefrom while coasting or back-pedaling, a brake-ring connected to the sprocket, a fixed ring sur* rounding the brake-ring, separate clamping-- pieces formed in the brake-ring adapted to be forced toward the center to grip the lock-nut, said clamping-pieces having cam-slots in their outer edges diminishing toward the front and adjacent to the fixed ring and a ball or roller arranged in each of said cam-slots.

4:. In combination in a coaster bicycle-brake, the wheel, the hub, the sprocket fitted thereto,

means for locking the sprocket to the hub when driving and for releasing it therefrom while coasting or back-pedaling, a brake-ring connected to the sprocket and having an annular wall on one face of which sections are made separate and free to be movedtoward and from the center,- springs forcing said sections radially, a fixed ring surrounding said- 1 In a back-pedaling brake, the hub,'a fric-" wall and sections having cam-slots diminishing in depth toward the front formed in their outeredges' adjacent to the fixed ring, balls or rollers in said cam-slots, and alock-nut secured to the hub'and-extending outwardly withinthe Wall and between the sections.

5. In combinationinafriotion-brake'mechanism for veloci'pedes, the hub, a' sprocket-- ring secured thereto, thesprocket fitted to the sprocket-ring, balls or rollers arranged in cam slots formed between the sprocket-ring and ,the sprocket to lock them together when the sprocket is turnedforward, andto release them" when the sprocket is held or turned back, a brake-ring connected withvthe sprocket having an annular wall on its outer face, op-

sections, said cam-slots diminishing in depth .toward the front, and a tapering lock-nut se- .cured to the hub and having an inclinedsurface fitting theinclined surfaces on saidclamp ing-sections. i a

6. In combination 1n aback-pedallng brake -p0sit e sections of said wall made separate and having an inclined surfacev on their inner edges, a ring surrounding said wall and sectionsand secured to the frame,rol lers arranged incam-slots formed between said ring and mechanism for velocipedes, the hub, a

sprocket-ring secured thereto having an enlarged 'frictlon-surface at r ght anglesito the hub and 'an outwardly-extending cylindrical "shank, said shank being formed with recesses diminishing in depth toward the rear and having pocke'ts'at the front ends, of a sprocket fitted to said cylindrical shank and also formed with recesses gradually diminishing toward the rear and terminatingwith shoulders at their front-ends, balls or rollers arranged in :saidrecesses looking the sprocketwhen turned forward to the sprocket-ring, a brake ring -IOO I05, secured to the sprocket and having an annular wall on its outer surface, separate opposite:

in back-pedaling the clamping pieces are I forced toward the center and sliding inwardly on thetapering lock-nut force the sprocket against the friction-surface on the' sprocketr1ng. 1 4 i 7 In combination in a friction-brake mechanism for velocipedes, the wheel, the hub formed at one end with a shoulder,-with a righthand thread and a smaller left-hand thread, a sprocket-ring fitted to the right-hand thread having at its inner end an annular portionextending at right angles to the hub, and an out wardly-extending cylindrical shank,said annular portion having an outwardly-extending margin, a fiber ring arranged within said margin and around the shank, said shank being formed on its periphery with cam slots or recesses diminishing in depth toward the rear; a sprocket fitted to said cylindrical shank and having in its edge adjacent thereto cam-slots diminishing in depth toward the rear, said sprocket being formed on its inner face with an annular groove fitting the outer margin of the sprocket-ring, balls or rollers arranged in said sprocket-slots; a brake-ring secured to the outer face of the sprocket and having an annular wall on its outer surface, and an enlarged face-plate near its inner surface; a fixed ring arranged around said annular wall and secured to the fork side, said ring being coun ter bored on its inner and outer edges, to fit said face-plate and an outer face-plate on the lock-nut; sections of said brake-ring wall made separate to form clamping-pieces, adapted to be moved toward the center against a tapering lock-nut, and formed on their inner edges with inclined friction-surfaces and on their outer edges adjacent to the inner surface of the fixed ring, with cam-slots diminishing in depth toward the front.

8. In a back-ped aling brake, the hub, a friction-surface thereon, the sprocket, means for locking the sprocket to the hub while driving and releasing therefrom while coasting or back-pedaling, a brake-ring connected to the sprocket having wedges suitably supported therein, cam-slots on their outer edges, rollers arranged in the slots of larger diameter than the narrower portion and of smaller diameter than the wider portion, and means for moving the wedges to and from the center while backpedaling to force the sprocket into frictional engagement with said friction-surface.

9. In a back-pedaling brake, the combination with the hub and a friction-surface thereon, of the sprocket, means for locking the sprocket to the hub while driving only, a brake-ring connected to the sprocket, clamping and wedging sections supported on the brake-ring, and means for moving said sections toward the center and against the sprocket to force the latter into frictional engagement with the friction-surface.

10. In a back-pedaling brake, the combination with the hub and a friction-surface thereon, of the sprocket, means for locking the sprocket to the hub while driving only, radially-movable clamping and wedging pieces suitably supported, and means for moving said pieces toward the center to force the sprocket against the friction-surface.

11. In a back-pedaling brake, the combination with the hub and a friction-surface thereon, of the sprocket fitted to turn freely and to move longitudinally on the hub, means for locking the sprocket to the hub while driving only, a brake-ring connected to the sprocket, radially-movable clamping and wed ging pieces supported on the brake-ring, and means for forcing the sections against the sprocket to force the latter against the friction-surface.

12. In a back-pedaling brake, the combination with the hub and a flat friction-surface thereon, of the sprocket, means for locking the sprocket to the hub while driving only, an element secured to the hub having an inwardly-inclined friction-surface,clampingand wedging pieces supported around said inclined surface, and means for forcing said pieces against the inclined surface, said latter means being operated by back-pedaling.

In testimony whereofl have hereunto signed my name.

JOHN ZIMMERMAN. Witnesses:

(J. C. SoIroENuoK, E. L. DARLING. 

